Internal-combustion engine and method of operating the same.



I H. E; DUNHAM. IN'ILEBNAL COMBUSTION ENGINE AND METHOD OF OPERATING THESAME.

' APPLICATION mum 1:20.11. 1913.

1,106,194. Patented Aug. 4, 191$ 5 SHEBHEET L.

*3 r-r-n rm I I E H. E. DUNHAM.

INTERNAL COMBUSTION ENGINE AND METHOD OF OPERATING THE SAME.

APPLICATION FILED DEC.17, 1913.

1, 106, 1 94. Patented Aug. 4, 1914 a 5 SHEETS-SHEBT2 w )3 H. E. DUNHAM.

INTERNAL COMBUSTION ENGINE AND METHOD or OPERATING THE 3 APPLICATIONFILED D2017. 1913. 1,106,1 94.

AME.

Patented Aug. 4, '1914.

5 SHESTSSHBET 3.

Wies. Ewe/L507. I

H. B. DUNHAM. INTERNAL COMBUSTION ENGINE AND METHOD OF OPERATING THESAME.

APPLICATION FILED DEC.17. 1913.

m. 4 m nmm E ma m a P Ira/6 02 51" 7/ mfl2w/ b Z (1 in 1 H. E. DUNHAM.

INTERNAL COMBUSTION ENGINE AND METHOD OF OPERATING THE SAME. APPLICATIONFILED DBO.17.1913.

11 O6, 1 94;. Patented Aug. 4, 19M

6 SHEETS-8HEET 6.

W61 Ja e/502.

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ASSIGNOR T THE Him/M03 "ASHINGZICJN, A CORPORATION 1,1552% FNfl l" 1.,AND METHOD OF OPERATING THE I-. T-ec.;ueation of Letters 2 stem.

a 8.12pm pi -err as Patented Aug. 4, 1914.

ere, filed June a, 1910, r This application filed December 17 i /=2FILL?! 2' re lie it known the citizen of the tv attle. in the cow=liililft0l1,liiku useful luiprovemi n Engines end H me: amt l \lo g:igto be a full, -i f the invention iuilleil in the art nuke and use il'aThis inientiozi lion engines of it" nding applica i n June ll, lull.an-J has sperial reference to engines of the You oycle type, althoughcertain phases of my improielm'nts are llliQ- isc applicable totwc-cycle engines as well.

The primary object of the invention is to provide for the pruclii'a ivthorough aiul complete combustion of the i-i l incl w -hat fuels of thelowest grail and oi" uni ous hinds can be employed with elimination ofthe cnrb'uiii/iiny au-tl u .l description 21 we will ci'uible others.a'hich it appertains to vi; to int rnal combusil iili' P of the engineparts. This re ult aitrunr l .iv' introducing into the engine or uot r(luring the operation thereof :1 quautu) of air which is considerably inex es of that required to support the combustion o; Illtl whichs'liflicicnt to can: C a puwiczall thoriur-jh oxillation :iiricons-eruption of thc lt foil n63. to n- 1:11. that the rl u i proper!ics oi lit-f lu-l are cLti lfV bnrn il without i'clmsiti'm of rz-rlrm(-r other 3c it l t spuzi' plug and the walls ei p um Llltl cylui'lcr. ialso propo fi' -l: air the win: sour-v who; to s ug-rut. th cornb== 1-ll: ui uilliu to avenge ti ;,:ine i order that prai fuel ('lnl aw.

all of he (lead. mac- 3 iin when the charge is ftjti ill mhuuat pcrimiin tron a quantity of combustion supporting air will naturally raise theamount of oxygen in the cylinder to an excess necessary 3 to produce thecomplete combustion of fuel Will i1 contemplated.

'l excess air referred to above is likewiw of value in producing arelatively high curl; li'fi i fln. with a consequent increase in power.and the compression is also made practicall; con tant or uniform at theignition point, without regardto the quantity of fuel fed in from theinspirator. which, of course. is much to be desired. The highcompression and the excess amount of oxygen prevent the fouling of theengine parts by partially burned fuel. and the practically constantcompression makes the ignition more reliable and punctual than has heretofore been possible.

The inv ntion likewise conten'iplates inr prorenients in certainfuitures of the en nine. and particularly, in the provision of improwllfuel supply mechanisnr designe'l to iu rca c the power and eilici ncy ofthe engine. and a ting either in conjunction with the'carlmrctcr, whichluttri' supplie -i primary harge tofurnish the initial heat wh nignited. or operating by itself mules cerain conditions to behereinafter explaineil. This makes it possible to run th engine on twokinds of fuel at the same time. by introducing; it into the evlimler attllll tl'tlll point at the same time, or cl-c with fuel ailniitt l ateither of thee points. The mlilitional fuel supply mean, preferabl itakes the form of an insp rator by means of which fuel of anyappropriate character (though I contemplate cspccially the 9 of lowgrade liquid oils in this our nection) is fed into the cylinder at thesuction stroke mixetl with a suppl v of air uniler pressure; and thisfuel, of which a number of klllllS may be uscil in connection with thesame in pirator. may be introrluceul into the cyliniler together with aquantity of wat r which is M) controlled as to enter the iyliiulcr onlwhen it will generate steam :lic'ein to :r it the power strolcc and beof liar-tale in woling: the cylinilcr walls.

in the ac ompanying drawing Figure l is a sille elevation of afour-cylinder engine constructe l in accordance with the, invention;Fig. *2 is a top plan \iOW of the same; Fig. 3 is a side elevation ofthe engine shown in Figs..l and 2; Fig. 4 is a sectional view of one ofthej cylinders of the engine'illustrated in Figs. 1, 2 and 3, certainparts being omitted for the sake of clearness; Fig. 5 is a sectionalview of a single cylinder engine constructed in accordance with theinvention, and Fig. 6 is a sectional view of the inspirator employed.

Although certain features of the invention are applicable to two cycleengines, a four-cycle engine has been illustrated in the drawings andthe invention will be described in connection therewith, as this is thepreferred embodiment.

Referring to the 'drawings, the construction illustrated in Figs. 1 to 4inclusive comoperated in an prises a plurality of cylinders A, eachhavinga piston B. In this form an auxiliary piston C ('Fi 4) is,providedto slide in and cooperate wit an extension or elongation D of thecylinder A, to serve as an air compressor, which will hereinafter bemore fully described. The pistons B and C ma be connected'in any desiredmanner to e ect their movement in unison, but preierauiy a sleeve 2serves this purpose. The crank case E contains the usual crank shaft(not shown) connected to the connecting rod F, which is preferablyivoted to the sleeve 0 at a point f. Each cylinder A is provided withthe ordinary water jacket G, and at the upper end or head portion eachcylinder is in communication with a fuel admission or firing chamberHinto which the usual spark plug I projects. Fuel is supplied to thischamber from the 'carbureter in' the usual way by means of an opening Jcontrolled by a spring pressed valve j at the junction of said pipe withthe firing chamber. The valve 7' is of the customary type and itisnormally held closed by its spring, though the creation of a partialvacuum in the cylinder A will cause the valve to be sucked downward awayfrom its seat in order to admit the carburetted air from the inlet J.The cylinder A is nitewise provided, preferably at the point indicated,with an exhaust valve L of the poppet type suitable manner,-such as Irthe cam 'l. T is valve coacts with a seat formed in a assage M whichcommunicates with a second exhaust passage m in the cylinder wall,intermediate of the length (if the cylinder, which port is controlled bythe piston B, as will hereinafter ap ear. The ex haust valve L isnormally he d seated by a spring 1, but it is raised mechanically at theproper time to effect the exhaust by means of the cam l.

As'previously intimated, a very essential part of the invention consistsin the introduction of a considerable quantity of air into the cylinderat such a time as to support and complete the combustion and again whenit is advantageous to scavenge the cylinder and drive out the burnedgases. This air must be under com ression if good re sults are to beobtaine so that such compression acting against the partial vacuum or atany rate the lower ressure which is Dresent in the cylinder, Wlll resultina remarka'bly quick and comparatively great in flux of fresh air intothe latter at the proper time. I prefer to compress the air either inthe extension D of the cylinder or in the crank case or base oftheengine itself, and I shall describe the invention as carried out inthat way but it should be understood that if desired the compression maytake place elsewhere. f"

In the formsho'wn in Figs. 1 to 4, atmospherio air is admitted to thecompressor portion D of the-cylinder through a suitable check valve 4tor the equivalent means preferably associated with the conduits N and O.The conduit N connects the com ressor portion D of the first cylinderwith the upper portion A of the adjacent cylinder,,as will be clear froman ins ection of Fig. 1. Likewise a second conduit 0 connects the lowerportion D of the, second cylinder with the, upper portion A of the firstcylinder. In the't'hird and'fourth cylinders, the upper and lowerportions of the cylinders are connected in a similarmanner, so that asthe piston B moves upwardly,the compressor piston C forces air throughthe conduit associated with its cylinder into the upper portion of theadjacent cylinder. Ports 0 are provided admit the compressed in thecylinder wall to air from the conduits N and 0, said ports beingcontrolled by the movement of the piston. These parts complete therequisite of my improved engine, in so far as complete combustion andscavenging are concerned, but inasmuch as I prefer to employ anadditional or auxiliary fuel supply mechanism, as previously described,for the purpose of increasing the efficiency of the engine, and enablingit'to be run very economically on low grade fuels of variouscompositions I i shall .now proceed to describe a preferred form of suchfuel supply mechanism and I shall then take up the operation of theengineas a whole. It should be stated, however, that under someconditions the auxiliary fuel supply may be altogether omitted, and itwill be suiiiciently apparent how the engine would operate under thesecircumstances.

The ,inspirator or injector mentioned above, by which the additionalsupply of fuel is effected, is preferably supplied with compressed aireither from the lower portion D of the cylinder or from the crank case,as will hereinafter more fully appear, and this air is fed into theinspirator without obstruction or obturation, though the passage of thefuel or fuels and of water or other liquid to the cylinder by means ofthe inspirator is suitabl controlled in the inspirator itself. Re erringparticularly to Fig. 6, it will be seen that I employ an inspirator Pcomprising a casting or casing adapted to be inserted into the cylinderWall. In the embodiment illustrated the inspirator is shown as adaptedto introduce one kind of fuel and also a liquid, such as Water, but itwill be evident that various kinds of fluids in diiferent combina ionsand in different numbers may be employed without modifying theconstruction of the in spirator very materially.

At the interior end of the inspirator P, which is in directcommunication with the cylinder A, said inspirator is provided with arestricted discharge opening or ozzle l, and said opening or nozzleleads directly into a longitudinal bore in the inspirator easing. Tbsbore eonnnunicates with a number of branch connections through which thefluils to be used (exclusive of the compressed air) are admitted, and inthe dev ice shown in the drawings the branch ,3 is intended to re eivefuel such, for example. as crude oil, from a fuel pipe 3, while thebranch. 4. receives water from a Water supply pip i. The branches 9, rare in "omuiuni nti n with longitudinal side pass s ti. 7. rxspectivelyformed in a tube or cas ng h inmahle lengthwise in the bore J of theinspirat i casing and having an air 1 ua- 'e 10 in onsmunicatimi withthe compressor C--D of the adjacent cylinder by means of a pipe orconduit 11. The passage 10 is arranged cc tral'ly of the casing 55 andat one end it terminates in a restricted opening l; which is inalinement with the discharge pening: 1 of the inspirator casing. Thepassagc-- (3, I leading to the fuel supply and the watcrsu plyrespectively are located at opposite sides of the air passage 12 andtheir outlet end, 43, 7 are formed in a flllS't()-('Oill(tll end wall ofthe casing 8 (toacting with a correspondingly inclined surface 13 in themain casing bore 9 in such a way that although the air passage 12 isalways in unobstructed coimnunication with the discharge opening 1. thefuel and water passages i, 7 may he clcsed by the engagement of theinclined end of the casing 8 with s: 'd surface 13, as indicated in Fig:3.

The casing 9 may able manner to con and water, but preferably hasassociated therewith a lever 14 which, when oscillated. turns the lasingF and due to the threaded portion l3 thereof colon-rating with athreaded portion on the bra ket 16, the casing h is made 7 or outwardlydepending the lever it is shifted. preferably a l operating rod 17, asbest shown in Fig. 1.

Check valves 18 are used in both the fuel upon which way The levers itare,

i be a tuated in any suit- 1 trol the supply of fuel each llbpil'tll'filto move iuwa dlv interconnected with a single and water branches 9 and4, respectively, and a check valve 19 is associated with the air inlet11. These valves permit the fuel water and air to be drawn into thecylinder on the suction stroke,but prevent any back flow from thecylinder through the inspirator when the pressure in the cylinderincreases.

The operation then is as follows :-On the suction stroke, viz., the downstroke of the piston, the earburetted air is supplied to the cylinder byway of the firing chamber H into which the charge is admitted by thelifti ng of the valve under the influence of the partial vacuum createdin the cylinder. At the same time, fresh air is admitted to the cylinder1 by means of the check valve 7L and is later compressedby the piston Con its upward stroke, as will be understood Of course when the pistonbegins its suclion stroke. it is well toward the top or head of thecylinder, leaving only the customary clearance space which, however, isin direct communication with the firing chamber. The conmressed airinlet port 0, together with the discharge opening Z of the inspiratorand the exhaust port m, are of course, closed directly by the pistonitself at the time that it begins its suction stroke, but It will beobvious that on a continuance of such stroke, the mixture of fuel andWater will be atomized into the cylinder by the action of the vacuum andthe incoming eomties-d air traveling from the lower portion l of theadjacent cylinder to the inpirator through pipe 11. It will be notedthat as the pistOns l) and C of one cylinder are moving down the pistonsof the adjacent cylinder are moving up. Hence on the suciion stroke ofpiston l) in Fig. 4, the inspirator is supplied with compressed air fromthe adjacent oinprcssor D, since said id-- jacent compressor is in theact of compress in;- the air while that associated with the ame cylinderin which the suction stroke occurs is nit-rely drawing in its charge ofair through valve n. The conduit 11 therefore supplying air to theinspirator I in Fig. 4- crosses the conduit ll and derives its airsupply from the adjacent compressor. as best h wn in Fig. 1. As the airfrom the comprcsr'oi' is under pressure, and as a partial (acunui existsin the cylinder on the suction st rc t he uncovering of the dischargeopentin inspirator will cause the air in the ipe 1 l to be sucked intothe cylinder at -i h s eed. mixed with the other incoming," Bride.whereby the cylinder is rapidly and plci lv tilled with a combustiblemixture 11 vi cd from two sources (the carburetor in i and theinspiraior) combined, however, wi h a large quantity of air. on the fur-.a movement of the piston at the same i the air inlet port 0 will beuncovered, l-is port is of considerably greater int! l of ard as lltarea than the discharge of the inspirator, the greater part of thecompressed air remaining in the compressor which supplies the inspirator will be delivered immediately into the'cylinder, and the latterwill be rapidly filled with a comparatively large body of fresh air tosupport and complete the combustion after the ignition of the charge.Owing to the fact that a vacuum still exists in the cylinder to acertain extent when the port 0 is uncovered by the piston, the greatdifference in pressure between the cylinder and the compressor willcause the compressed air to enter the cylinder with remarkable rapidity,and this air is suflicient in quantity to effect practically a completecombustion of the entire fuel content of the cylinder even when fuels ofvery low grade are used and regardless of the condition of mixture andproportions of the carburetted mixture. The fuel may be too rich, ofcourse, to ignite if it is notproperly controlled, but if there is any inition at all the body of air present issu cient to.produce apractically perfect and complete combustion, with the attendantelimination of smoke, smell and fouling of the engine parts.

It will be understood that the insplrator and the compressed air inlet 0remain uncovered during the initial part of the compression stroke, toenable a full charge of fuel and air to be introduced, but on thecontinuance of the compression stroke, at which time, of course, theinlet valve 7' .has been closed, the port 0 will be closed and shortlyafter the inspirator discharge I will be closed. In the meantime a freshbody of air will be sucked into the cylinder D through the check valven. It is evident that the supply of fuel and water introduced throughthe inspirator may be regulated by the mechanism previously described,but air will pass into the cylinder from the inspirator as long as thepressure in the cylinder is less than that in the compressor. As thepiston continues its upward movement after closing the aforesaid portsand discontinuing the air and fuel supply, the body of air, fuel andwater is highly compressed and this compression continues until thepiston arrives at or near its upper dead point, at which time theexplosive or combustible mixture is ignited by the spark plug I and anauxiliary plug I which may be provided, if desired. The completecombustion of the fuel is then obtained by the comparatively greatamount of oxygen present, as previously explained, and the piston passesthrough the working stroke or cycle under the influence ofthe expansionof the gases and of the steam generated by the introduction of the waterinto the cylinder into gases, whereby a working stroke of maximum poweris ob tained. Not only is the working stroke of l the piston effected bythe ignition and expansion of the fuel, which is completely burned bythe excess of air present, but the air itself is a very important factorin the actual production of pressure on the piston. It will beremembered that the air taken from the compressor is under compressionand considerably above atmospheric pressure when it enters the cylinder,and on the upward or compression stroke of the piston such compressionof the air will be further increased throughout the length of saidstroke. This comparati ely high and practically uniform compression,which is so important in producing a reliableignition, as aboveexplained, is also effective in raising the heat of the already warm airto a co nsidcrable degree, and further heat is absorbed from thecylinder walls and piston, so that on the working stroke, when the airis still further heated by the ignition of the charge in the firingchamber and in the clearance space, expansion of the air will takeplace, in proportionto the heat abengine. At or near the end of theworking stroke the exhaust valve L is opened by its cam, so that theescape of the products of combustion through the exhaust passage M andport m is begun, and at the same time the compressed air inlet 0 isopened to admit air from the compressor, which in this case isscavenging air. When the scavenging air passes into the cylinder itpasses across the same and-drives the exhaust gases directly through theport m and passage M into the exhaust pipe. The port m is closedhowever, early in the exhaust stroke of the piston, and the furtherscavenging of the cylinder is produced by the piston itself in carryingupward the body of introduced air and thereby forcin out the remainingproducts of combustion through passage M, and exhaust valve. Obviously,the amount of air introduced into the cylinder for scavenging purposesmust be such that while it will completely clear the cylinder of burnedgases, first by way of port m and then by way of passage M, very littleof such air is driven out into the exhaust pipe, for it is highlyadvisable to use all of this air as a combustion supporting medium intowhich cylinders'are left full of fresh air instead .of

dead gases and the introduction ofair under pressure for the specialpurposes of starting theengine is rendered unnecessary:

. In Fig. 5 a single cylinder engine is shown in-whichthe air iscompressed in the crank case. For this purpose, a check valve 'n' isprovided in the crank case, E, so that 7 when'the piston B makes itsupward stroke,

it draws in a charge'of air into the crank case. On the down stroke ofthe piston it serves to compress the charge and supplies. the inspiratorP through a connection 7) in the same manner as hereinbefore describedin connection with the four-cylinder engine. In the single cylinderengine the air is preferably admitted from the crank case to thecylinder through a port 0 in the cylinder wall communicating with thepassage 0" in the cylinder wall. In this form the admission and exhaustvalves 7" and L respec tively have been placed in slightly differentpositions, but the general operation of the form disclosed in Fig. 5 isidentical with that of the four-cylinder engine hereinbefore describedin detail. 7 What I do claim as my invention, and desire to secure byLetters Patent, is

1. In an internal combustion engine, the combination with the cylinderand the piston, and means to supply fuel to the cylinder on the suctionstroke, of means to supply air to the cylinder at the ends of thesuction and Working strokes, for combustion-supporting and scavengingpurposes respectively, and an additional fuel supply means operated tosupply fuel to the cylinder near the end of the suction stroke, whichfuel is consumed in the excess of air in the cylinder.

2. In an internal combustion engine, the combination with the cylinderand piston, and means for supplying carbureted air to the cylinder onthe suction stroke, of means for supplying air to the" cylinder onalternate outward strokes, and an additional fuel supply means forspraying fuel into the cylinder near the end of the suction stroke, suchadditional fuel being thereby, mixed with the excess of air in thecylinder? 3. In an internal combustion engine,the combination with thecylinder and the piston, and the means for supplying carbureted air tothe cylinder on the suction stroke, of means for supplying air to thecylinder on alternate outward strokes of the piston, and an inspiratorin the cylinder wall so controlled by the piston as to permit liquidfuel to pass into the cylinder in addition to the carbureted charge.

4. In an internal combustion engine, the combination with'the' cylinderand the piston, and the means for supplying carbureted air to thecylinder onthe suction stroke, of means to supply air to the cylinder onalternate outward strokes of the piston, and means operative on thesuction stroke of the piston to supply the cylinder with additional air,said air being mixed with an additional charge of fuel in liquid form. 1

5. In an internal combustion engine, the

combination with the cylinder and the piston, and the means forsupplying carbureted air to the cylinder on the suction stroke, of meansfor supplying air to the cylinder near the end of the suction stroke,means to introduce an additional charge 'of fuel into the cylinder tomix with such air, and means for varying the amount of fuel sointroduced.

6. In an internal combustion engine, the combinationwith the cylinderand piston, and the means for supplying carbureted air to the cylinderon the suction stroke, of means to supply air under pressure to thecylinder near the end of the suction stroke, and means to introduce intothe cylinder near the end of the suction stroke an additional body ofair mixed with fuel in liquid vacuum in the cylinder.

8. In an internal combustion engine, the combination of a cylinder andpiston, means to admit carbureted air to the cylinder on the suctionstroke, a compressor in which air is compressed, an inspirator in thecylinder wall, means to supply liquid fuel to said inspirator, and aconnection between said inspirator and the compressor which forces suchliquid fuel into the cylinder near the end of the suction stroke.

9. An internal combustion engine provided with a cylinder, having meansto supply the cylinder with carbureted air on the suction stroke, meansto supply surplus air to the cylinder on the suction stroke, and meansoperative on the suction stroke to supply the cylinder with liquid fuel.

10. The method of operating an internal combustion engine which consistsin draw plete.

ing carbureted air into the cylinder from the beginning of the suctionstroke of the piston, introducing liquid fuel into the cyl:

inder later on in the suction stroke, such liquid fuel being sprayedthrough the cylinder wall under pressure, then, as the piston nears theend of the suction stroke, admitting a relatively-large quantity ofcombustion-supporting air to the cylinder, cutting off such air at thebeginning of the compression stroke, then cutting ofi the liquid fuel,

and firing the mixture in the cylinder when the compression stroke issubstantially com 11. In an internal combustion engine, the combinationof acylinder having a firing chamber associated with the head portionthereof, a piston in said cylinder, an air compressor a by-pass leadingfrom the air compressor to the lower portion of the cylinder andcontrolled solely by the position of the piston, anexhaust port in thecylinder wall substantially opposite the inlet port of said by-pass, andan inspirator inv the cylinder wall above the inlet port of saidby-pass, said inspirator being in communicatlon with the compressor andbeing also controlled by the piston, whereby the air under pressure isadmitted to the cylinder inder and controlled solely by the position,

of'the piston, an exhaust port in the cylinder wall substantiallyopposite the inlet port of said by-pass, an insplrator in the cylinder iwall above the inletport of said by-pass, said inspirator'being incommunication with the compressor and being also controlled by thepiston, whereby the air under pressure is admitted to the cy linder fromthe inspirator during part of each suction stroke of the piston, andmeans to supply fuel to the inspiratorduring the suct on' stroke sothatsuch fuel is fed into the cylinder by means of air under pressure. i

In testimony whereof I afiix my-signature, in presence of two witnesses.

HERMON E. DULlHAM.

Witnesses:

CHAS. J. ONEILL, VERNON T. HOUGHTON.

